In order for a mobile device to determine its geographic location using the Global Positioning System (GPS), it must first search for and acquire signals from GPS elements, such as satellites. This process can be time consuming.
To reduce the amount of time required for the mobile device to acquire its location, many modern wireless communication networks, such as Worldwide Inoperability for Microwave Access (WiMax) and long-term evolution (LTE) networks, typically provide network assisted GPS capability. Network assisted GPS allows the network to aid the mobile device in determining the mobile device's geographic location by providing the GPS elements with signals that the mobile device should acquire. Thus, network assisted GPS obviates the need for the mobile device to search for the elements itself. Removing the mobile device's need to search for GPS elements reduces the time needed for the mobile device to determine its geographic location.
At times, a wireless service provider may offer services over a variety of communications networks, such as 3G and 4G networks. However, in these situations carriers are faced with many challenges to the efficient and cost effective provisioning of network assisted GPS. For example, simply deploying duplicate systems can be unnecessarily expensive. Even alternatives to duplicate systems—such as utilizing back end systems compatible with multiple networks—can lead to overly complex and costly designs.
In a particular example, present network assisted GPS solutions utilize the location of a serving base station when selecting a preferred set of satellites with which a mobile device should communicate in order to establish its location. To accomplish this, an authorization system that initially granted the device access to the network is queried by a positioning sub-system for the identity of the serving base station. Merely duplicating this system would result in multiple positioning sub-systems, thereby increasing costs. Likewise, configuring the sub-system so that it is capable of communicating with authorization systems in multiple networks also increases costs.